1. Field of the Invention
The present invention relates to rollers that have a sleeve that is removably mountable on the core of the roller. This invention primarily relates to those rollers that are used in the can manufacturing industry to apply a surface coating to the cans and also to the industries that utilize rollers for graphics, conveying, laminating or spreading a coating on another surface.
2. Description of the Prior Art
Rollers used in the can manufacturing industry, and other industries, usually have a cover made of soft material that must be frequently replaced due to wear. The cover is bonded to a metal core. Field replacement of the covers, the removal of an old cover and the bonding of a new cover to the existing core, was found to be too difficult and inefficient for the users to accomplish. Therefore, repairs are accomplished at a roller manufacturing plant or at repair centers established for this purpose. This requires the user to maintain in their inventory a fairly large number of rollers and to ship the worn or damaged rollers for repair. Shipping costs are high due to the weight of the metal core. Attempts have been made to reduce the cost of such repair by manufacturing a sleeve, with the outer cover bonded thereto, that is removably mountable on the metal core. A U.S. Pat. No. 3,771,206 issued to James Brown discloses a roller with a removable covered sleeve that is secured to the metal core by lugs that engage notches in the sleeve at one end of the core and a clamp mounted at the other end to hold the sleeve onto the metal core.
U.S. Pat. No. 4,178,664 issued to Nelson McLoughlin discloses a roller with a replaceable sleeve that is attached to the rollers' metal core by friction and locking nuts.
These devices may have been successful at the lower rates of manufacturing of 300-600 cans per minute that require rotation of the roller of approximately 150 to 400 rpm. However, at higher rates of manufacturing currently utilized by the can manufacturing industry, approximately 1,700-2,200 cans per minute, the rollers are rotated at approximately 400 to 600 rpm; at these speeds the sleeves do not remain concentric with the roller core causing skips in the coating being applied.
Currently the users of these rollers ship the entire roller to the manufacturer or repair center for replacement of the bonded covering. Therefore, there is still a need for a sleeve that is cheaper to ship, easy to attach in the field and one which will maintain its concentricity in relation to the core axis during the high rates of rotation currently used.